Fine turf grass species are grown on golf course greens, fairways and tee boxes, as well as turf farms and many other locations. In northern regions, such as Canada and the northern United States, which are subject to temperate climates in the late summer and early fall and snow conditions in late fall and early winter certain moulds such as dollar spot, Sclerotinia homeocarpa, and snow molds, such as Microdochium nivale, Typhula incarnata and Typhula ishikariensis, represent a chronic problem for turf grass growers.
If left untreated in the late summer and fall, turf grass is predisposed to damage caused by Sclerotinia homeocarpa in the late summer and fall and the snow molds in late fall and over winter to spring. S. homeocarpa attacks most turf grasses grown in the South. Bent grass, common and hybrid bermuda grass and zoysia are most susceptible to S. homeocarpa attacks. The dollar spot disease occurs from spring through fall, and is most active during moist periods of warm days (about 70° F. to about 85° F.) and cool nights (about 60° F.) in the spring, early summer and fall.
Where the mold infection is extensive, the recovery of the turf grass can be delayed well into the growing season and seriously affect the ability of the turf grass to recover, leaving areas of dead patches. Further, turf grasses weakened or damaged by these molds are extremely slow to recover in the spring and are often invaded by undesirable opportunistic weedy grass species such as creeping bent grass (Agrostis palustris) and annual bluegrass (Poa annua).
A typical snow mold prevention program requires a mold inhibiting fungicide to be applied to turf grass prior to permanent winter snow cover. Typical programs consist of three applications prior to permanent snow cover and an additional application after the snow cover is gone in the spring. Several commercial fungicide products have been approved for use against dollar spot and snow mould species.
COMPASS (trifloxystrobin; (αE)-α(methoxyimino)-2-[[[(E)-[1-[3-(trifluoromethylphenyl]ethylidine]-amino]oxy]methyl]benzenacetic acid methyl ester) is an aromatic dioxime fungicide which has been approved for the control of leaf spot, Fusarium patch and brown patch diseases in turf grass. Trifloxystrobin is a quinone outside inhibitor (QoI) and a member of the class of aromatic dioxime fungicides described in U.S. Pat. No. 5,238,956, the contents of which are incorporated in their entirety herein.
ROVRAL GREEN GT (iprodione; 3-(3,5-dichlorophenyl)-N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecaboximide) is a dicarboximide fungicide for pink snow mold control at a rate of 250 ml/100 m2 and for gray snow mould control at a rate of 375 ml/100 m2. Iprodione is a member of the class of 3-phenyl hydantoin compounds described in U.S. Pat. No. 3,755,350, the contents of which are incorporated in their entirety herein. The effectiveness of iprodione to control the spread of snow mold in turf grasses (especially the gray snow molds T. incarnata and T. ishikariensis) is highly variable due to the varying amounts of fungus inoculums, the varying length of snow cover under which snow mould inoculums thrive and the varying winter temperatures that exist across the country from year to year. Thus, in order to effectively control against a spectrum of snow moulds a relatively high dose may be required as well as multiple applications.
Phthalocyanines are known pigments having many applications, such as pigments for inks and coatings and even for turf grass paints. See, for example, DE 2,511,077, the contents of which are incorporated in their entirety herein, and JP 03/221576, the contents of which are incorporated in their entirety herein. Copper phthalocyanine has been used, but only in combination with certain other active ingredients, for enhancing turf quality. For example, U.S. Pat. No. 5,599,804, the contents of which are incorporated in their entirety herein, describes a method of combating fungi and enhancing turf quality in turf grass by applying in specific ratios certain phthalocyanines in combination with phosphorous acid or an alkaline earth metal salt thereof or with certain monoester salts of phosphorous acid. U.S. Pat. No. 5,643,852, the contents of which are incorporated in their entirety herein, describes a method of enhancing turf quality in turf grass by applying in specific ratios certain phthalocyanines in combination with (i) phosphorous acid or an alkaline earth metal salt thereof or certain monoester salts of phosphorous acid and (ii) certain ethylene bisdithiocarbamate contact fungicides. U.S. Pat. No. 5,336,661, the contents of which are incorporated in their entirety herein, describes a method of treating bent grass and enhancing turf quality by applying in specific ratios (i) certain monoester salts of phosphorous acid and (ii) a metallic ethylene bisdithiocarbamate contact fungicide. This patent also describes a specific composition containing a combination of aluminum tris(O-ethylphosphonate) (fosetyl-al) and a manganese-zinc ethylene bisdithiocarbamate complex (mancozeb) used in a form (FORE fungicide) believed to have contained an unknown amount of the phthalocyanine compound Pigment Blue 15.
It has been unexpectedly discovered that compositions comprising any two of the following three fungicides: (i) a QoI inhibitor fungicide, (ii) a contact fungicide, and (ii) a demethylation inhibitor; and certain pigments show superior mold control abilities than compositions with similar fungicides but without the pigments.